At the 2002 IA Summit, while talking about New Roles in Information Architecture, I showed the number of Google Hits for a handful of related search terms.
Since then, it's been interesting to periodically review the annual growth rates of these user experience memes, and fun to explore the questions they raise.
For instance, why is usability continuing to outpace information architecture and user experience? And why is findability the fastest growing meme on the list?
Somewhat related is the growth in non-English terminology:
http://blog.vanderbeeken.com/2005/12/experience_desi.html